Gunning Transceiver Logic (GTL) relates to a type of logic signaling typically used to drive electronic backplane buses. GTL uses smaller voltage swings than used in Transistor-Transistor Logic (TTL) or Complementary Metal Oxide Semiconductor (CMOS) Logic. Moreover, GTL employs symmetric parallel resistive terminations at each end of a signal line to avoid signal wave reflections.
FIG. 1 illustrates conventional GTL system 10 including receiver 11 and transmitter 12. Receiver 11 and transmitter 12 and connected via bus 13, and each terminates bus 13 with resistance 14 that is substantially equal to a resistance exhibited by bus 13. The dotted arrow illustrates a DC current path that exists in a case that transmitter 12 drives a “0”. The DC value of this current has been measured at 13 mA for some designs, and exists at each GTL I/O pin. Such power drain is often unsuitable, particularly for mobile systems.